| Zeaxanthin | |
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4-[18-(4-hydroxy-2,6,6-trimethyl-1-cyclohexenyl)-3,7,12,16-tetramethyl-octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]-3,5,5-trimethyl-cyclohex-3-en-1-ol |
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Other names
β,β-carotene-3,3'-diol |
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| Identifiers | |
| CAS number | 144-68-3 |
| PubChem | 5280899 |
| ChemSpider | 4444421 |
| UNII | CV0IB81ORO |
| ChEBI | CHEBI:27547 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C40H56O2 |
| Molar mass | 568.88 g/mol |
| Appearance | orange-red |
| Melting point |
215.5 °C, 489 K, 420 °F |
| Solubility in water | insol. |
| Related compounds | |
| Related compounds | lutein xanthophyll |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Zeaxanthin is one of the most common carotenoid alcohols found in nature. It is important in the xanthophyll cycle. Synthesized in plants and some micro-organisms, it is the pigment that gives paprika (made from bell peppers), corn, saffron, and many other plants and microbes their characteristic color.
The name (pronounced zee-uh-zan'-thin) is derived from Zea mays (common yellow maize corn, in which zeaxanthin provides the primary yellow pigment), plus xanthos, the Greek word for "yellow" (see xanthophyll).
Xanthophylls such as zeaxanthin are found in highest quantity in the leaves of most green plants, where they act to modulate light energy and perhaps serve as a non-photochemical quenching agent to deal with triplet chlorophyll (an excited form of chlorophyll), which is overproduced at very high light levels, during photosynthesis.
Animals derive zeaxanthin from a plant diet. Zeaxanthin is one of the two primary xanthophyll carotenoids contained within the retina of the eye. Within the central macula, zeaxanthin is the dominant component, whereas in the peripheral retina, lutein predominates.
As a food additive, zeaxanthin is a food dye with E number E161h.
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Lutein and zeaxanthin have identical chemical formulas and are isomers, but they are not stereoisomers. The only difference between them is in the location of the double bond in one of the end rings. This difference gives lutein three chiral centers whereas zeaxanthin has two. Because of symmetry, the (3R,3'S) and (3S,3'R) stereoisomers of zeaxanthin are identical. Therefore, zeaxanthin has only three stereoisomeric forms. The (3R,3'S) stereoisomer is called meso-zeaxanthin.
The principal natural form of zeaxanthin is (3R,3'R)-zeaxanthin. The macula mainly contains the (3R,3'R)- and meso-zeaxanthin forms, but it also contains much smaller amounts of the third (3S,3'S) form.[1]
Several observational studies have connected high dietary intake of foods providing zeaxanthin with lower incidence of age-related macular degeneration (AMD), most notably the Age-Related Eye Disease study (AREDS).[2][3] There is currently insufficient evidence to assess the effectiveness of dietary or supplemental antioxidants in treatment or primary prevention of ARMD, or the formation or progression of cataracts.[2][4] Any benefit is more likely to be apparent in subpopulations of individuals exposed to high oxidative stress, such as heavy smokers or those with poor nutrition.[5] In 2005, the US Food and Drug Administration rejected a Qualified Health Claims application by Xangold, citing insufficient evidence supporting the use of a zeaxanthin-containing supplement in prevention of AMD.[6]
Zeaxanthin is one of the most common carotenoid alcohols found in nature. It is the pigment that gives paprika (made from bell peppers), corn, saffron, and many other plants their characteristic color.[7] Zeaxanthin breaks down to form picrocrocin and safranal, which are responsible for the taste and aroma of saffron.
Foods considered good sources of lutein and zeaxanthin include eggs, spinach, goji berry, kale, turnip greens, collard greens, romaine lettuce, broccoli, zucchini, kiwifruit, corn, garden peas, swiss chard and Brussels sprouts.[3]
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